This is an essential, it allows you to play many Halo Custom Edition single player maps and firefight maps simply. I also recommend downloading Open Sauce which you can get here: I highly recommend downloading HAC 2 so you can download maps to servers that are playing maps you don't have.
I've tried to pick maps that are of high quality and could reasonably be compared to the quality of official maps. I made this map compilation because I find that most of Halo Custom Editions servers play only stock maps while there is an abundance of great user created maps. These maps were made by numerous authors over the many years Halo Custom Edition has been released. This Map Pack is a compilation of many Halo Custom Edition Maps that I found were of high quality and were favored by most of the Halo CE community.